<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8"/>
        <title></title>
        <style type="text/css">
            #p1 {font-weight: 100;}
            #p2 {font-weight: 400;}
            #p3 {font-weight: 700;}
            #p4 {font-weight: 900;}
        </style>
    </head>
    <body>
        <p id="p1">字体粗细为:100(lighter)</p>
        <p id="p2">字体粗细为:400(normal)</p>
        <p id="p3">字体粗细为:700(bold)</p>
        <p id="p4">字体粗细为:900(bolder)</p>
    </body>
</html>